Demolition/Dismantling Within Live Petrochemical PlantConnell Brothers completed a complex task within a live petrochemical plant at Shell Stanlow Manufacturing complex at Ellesmere Port.
Prior to commencement of the works Connell Brothers operatives attended and successfully passed the Shell “Permit to Work Acceptors Course”, and the Shell Site Induction. Once on site every operative attended the Unit 2700 Plant Specific Safety Induction carried out by the plant safety officer highlighting the permit to work and the clearance system that had to be strictly adhered to.
The task involved the safe dismantling of the CO plant together with the 27 metre high cold box. The plant included columns, vent stacks, condensers, vessels, tanks, a very large high pressure compressor together with all associated pipework and the removal of cables to the battery limits.
This work was carried out using cold cutting techniques involving the use of a high reach excavator fitted with a suitable hydraulic shear attachment. The excavators also had to be fitted with a specialised spark arrestor on the exhaust suitable for working in highly flammable areas. Operatives used air driven reciprocating saws together with other cold cutting tools.
The work commenced using a 35 tonne excavator equipped with hydraulic shear attachment, all the lower level plant and equipment was removed making way for the dismantling of the cold box.
The high reach excavator reduced the height of the cold box down to approximately 10 meters from ground level and then a second excavator fitted with a shear attachment razed it to the ground.
The task also involved the removal of 25 redundant pipes, several lagged with fibreglass, from the overhead two tier pipe rack. The pipework ranged from between 50 mm and 600 mm diameter and had been used to transfer various products including caustic, naptha, nitrogen, vent gas, cobalt, fuel gas, hydrogen, to mention but a few.
The overhead pipe rack, some 280 metres long, had to be fully scaffolded in its entirety on two different levels so that all the pipes could be accessed to carry out the work safely. All these lines had to be cold cut into small manageable sections, weighing 25 kg or less. The pipework ran between live plants Syn gas, Linevol and Neodol and over an analyser house. All of a very volatile nature contributing to the difficulty of the operation.
All operatives had to wear CO monitors at all times throughout the task as well as a “Shell Appointed Gas Tester” being permanently in attendance.
The pipework had been drained down and purged but, some product was still present. Therefore the pipes had to be blown through using compressed air back to the plant interceptor. This work was carried out as a joint venture between the client and ourselves.
During the work it was noticed that two of the lines had a significant amount of solid product inside therefore the work ceased. It was brought to the attention of the client and the operatives involved in the task were advised by the client to wear RPE, and once cut, to wrap the ends of the pipes with visqueen and duct tape for safe removal.
All the pipework, along with the contaminated pipes, were lowered down to ground level using a Tele-Handler and then segregated into the relevant skips for recycling. The contaminated pipes were sent back to Shell’s energy recovery plant for cleaning.
Throughout the works Connell Brothers H&S advisors carried out safety inspections every 2 weeks. Shell Health & Safety Inspectors carried out weekly inspections of the works and due to the efforts of all no accidents, incidents or injuries occurred on the project.
The final item recorded on the project close out meeting states that;-